arjun2,
The layers should be converted correctly from AutoCAD DWG to AI. Stacking order can get changed, but you can move the layers in AI up or down to fix that part.
The block issue is a problem, because they get converted to symbols, which are independent of one another. You could export individual blocks out of AutoCAD as DWG, save as AI or PDF in AI, then place them where they need to be. That can be a pain - time consuming.
You should be able to tweak the lineweights and font strokes in AutoCAD before you export. That might help. I am assuming you do not have a lot of AutoCAD experience. If you don't, you might want to brush up a little on AutoCAD. Some of the things you are describing would be much easier to do in AutoCAD.
If you need to do it in AI, at least get the files in AutoCAD to export the correct fonts and linetypes as DWG. The rest in AI will be easier. If you have an example DWG, and also the end result in AI (of what you are looking for), upload a link to them, and I can possibly advise you on a easy path. When you are talking isometric and exploded views, it all depends on how the files are created in AutoCAD.
